1. Field of the Invention
The invention relates generally to apparatus and methods for providing interrupts in computer systems and, more particularly, to interrupt systems implemented in computer systems employing object-oriented software.
2. Description of the Related Art
Computer systems operate, in general, by executing a series of specific instructions contained in xe2x80x9cprogramsxe2x80x9d stored in memory. However, the computer must also respond to randomly occurring external and internal events called xe2x80x9cinterruptsxe2x80x9d, such as a user pressing a key on a keyboard or a printer signaling for more data to print. The computer must suspend normal processing and temporarily divert the flow of control from the stored program to another program called an xe2x80x9cinterrupt handlerxe2x80x9d routine.
Interrupt processing is performed by the operating system (xe2x80x9cOSxe2x80x9d) software of both computers operating traditional software known as xe2x80x9cprocedural programming,xe2x80x9d and more recent systems employing software developed using object-oriented programing techniques. However, prior art object-oriented interrupt management systems have a number of limitations that affect both the portability and performance of the OS. That is, it would be desirable to provide an interrupt system to allow operating systems to be used with many different types of CPUs. Moreover, it would be desirable to provide increased speed and efficiency in handling interrupts by the operating system. The apparatus and methods of the present invention are designed to overcome all of these current limitations, providing with a portable and high performance interrupt management system.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the methods, apparatus, and articles of manufacture particularly pointed out in the written description and claims hereof, as well as the appended drawings.
To achieve these and other advantages, and in accordance with the purpose of the invention as embodied and broadly described, the invention provides a method for processing interrupts in an object-oriented computer system having a CPU, a memory containing a microkernel, a plurality of device constituting sources capable of generating interrupts, a plurality of drivers each associated with one of the sources, and a system database. The method comprises the steps of creating a device entry in the database for each of the devices, creating an interrupt source tree in the database comprising a plurality of source tree entries each comprising an object representing one of the sources, and implementing an interrupt registration interface comprising methods which install and remove interrupt management software components associated with each source in a corresponding source tree entry. The method further comprises the steps of cross-referencing each of the device entries with a corresponding one of the source tree entries, responding to an interrupt generated by a device by causing a single interrupt dispatcher to execute and identifying the device to the interrupt dispatcher; and processing the interrupt with a handler invoked by the interrupt dispatcher and corresponding to the identified device.
In another aspect, the invention includes apparatus for processing interrupts in an object-oriented computer system having a CPU, a plurality of devices constituting sources capable of generating interrupts, and a plurality of drivers each associated with one of the sources. The apparatus comprises a plurality of interrupt management software components supplied by the drivers each associated with an interrupt source; a memory containing a database having a device entry for each of the devices; an interrupt source tree comprising a plurality of interrupt source tree entries each comprising an object representing at least one of the sources and cross referenced to a corresponding device entry, each of the interrupt source tree entries including a reference to at least one of the interrupt management software components; and a single interrupt dispatcher for responding to an interrupt identified by the CPU by executing a corresponding interrupt management software component specified by an interrupt source tree entry corresponding to the identified device.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate one embodiment of the invention and, together with the description, serve to explain the principles of the invention.